error[E0277]: the trait bound `(): Trait fn(&'b u32)>` is not satisfied --> $DIR/hrtb-exists-forall-trait-contravariant.rs:34:5 | LL | foo::<()>(); | ^^^^^^^^^ the trait `Trait fn(&'b u32)>` is not implemented for `()` | = help: the following implementations were found: <() as Trait> note: required by `foo` --> $DIR/hrtb-exists-forall-trait-contravariant.rs:8:1 | LL | / fn foo() LL | | where LL | | T: Trait fn(&'b u32)>, LL | | { LL | | } | |_^ error: aborting due to previous error For more information about this error, try `rustc --explain E0277`.